The Facts

Alzheimer's disease has a major impact on the health of Canadians. About 570,000 Canadians suffer from some type of dementia (mental deterioration), and about 60% of these have Alzheimer's disease. The Alzheimer's Society of Canada estimates that the annual cost to Canadians to care for those living with dementia is over $10 billion.

There will be over 1 million Canadians living with dementia by the year 2038, largely because the "baby boom" generation (people born between 1946 and 1960) will have reached old age.

We still don't understand exactly how Alzheimer's disease damages the brain. Somehow, cells are damaged and eventually die in different areas of the brain. The damaged areas of the brain contain abnormalities called amyloid plaques and neurofibrillary (or tau) tangles. The death of brain cells leads to dementia, characterized by memory loss, impaired judgment, and behavioural changes.

Eventually, the person loses their speech as well as their bladder and bowel control. People with Alzheimer's typically die of infections such as pneumonia or other medical problems. Most people live for about 8 to 10 years after diagnosis, but some have lived for up to 20 years.

Each case of Alzheimer's usually affects at least two lives: the person with the condition, and the patient's spouse or child who gradually becomes a full-time caregiver as the disease progresses. Caring for an individual with Alzheimer's can be demanding and stressful. Many caregivers must eventually face the difficult decision of placing their loved one in institutional care.

Causes

With Alzheimer's, we look more at risk factors than direct causes.

There may be a genetic factor in Alzheimer's disease, since we know it runs in some families.

Familial autosomal dominant Alzheimer's disease (FAD) is the name given when Alzheimer's disease is clearly passed on from generation to generation in a family. It typically comes on before the age of 60, and 3 familial genes have been identified so far, called the PS1, PS2, and APP genes. FAD only explains about 5% of all Alzheimer's disease cases, however.

Another type of Alzheimer's disease, sporadic Alzheimer's disease, also runs in families, but to a much lesser degree. This type of Alzheimer’s disease is due to a combination of risk factors, including envirmonment, lifestyle, and genes.

Even if no one in your family has had Alzheimer's, you can still get sporadic Alzheimer's disease. Most researchers believe there are other genes that can make people susceptible to Alzheimer's disease, but genes alone aren't enough – some other trigger has to set off the disease process.

Possible risk factors include:

head injury: Studies show that people who have suffered concussions are more likely to develop Alzheimer's later on.

vascular disease: Coexisting small strokes increase the risk and severity of memory problems in Alzheimer's disease.

inflammation: People with arthritis are less likely to get Alzheimer's. It is speculated that the medications used to reduce inflammation in arthritis may have a beneficial effect on an inflammatory process in the brain.

gender: Women are nearly twice as likely as men to suffer from Alzheimer's (this is due to the increased life expectancy of women, not due to gender).

education: Research suggests that better educated people are less prone to Alzheimer's. Those who already have the disease do better if they keep mentally active – an unused brain may deteriorate faster.

toxins (e.g., aluminum, pesticides, second-hand smoke, and air pollution): A controversial and unproven theory links aluminum in drinking water to senile plaque formation. Earlier studies hinted at a connection with aluminium, but this is not supported by recent studies that are larger and better designed.

prions: Some scientists speculate that prions, tiny infectious particles made of protein, may be involved in Alzheimer's disease by infecting the brain.

cholesterol: Recent reseach has linked high LDL-C (low-density lipoprotein cholesterol) levels with increase risk of AD, although the connection is complex. Healthy blood vessels do not allow LDL to pass into the brain tissue. More reseach is being conducted to study how this cholesterol passess into the brain.

Symptoms and Complications

Mild forgetfulness is normal with advancing age, but healthy older people are usually good at remembering what's most important to them. There is reason for concern if they start forgetting what they were just doing, get lost in their own neighbourhood, or start displaying uncharacteristic or inappropriate behaviour. If your husband is always misplacing his keys, it may mean nothing. If he starts leaving them in the fridge or the sugar bowl, it may be cause for concern.

One of the most recognizable symptoms of Alzheimer's disease is a speech problem, such as a person choosing the wrong words, or not understanding simple sentences. Problems with numbers are also common. These are the most reliable signs of early-stage Alzheimer's disease. Other early signs include forgetfulness about recent events (loss of short-term memory), trouble with tasks such as housework or balancing a chequebook, and poor judgment.

In the later stages, people with Alzheimer's disease begin to have trouble caring for themselves and recognizing friends or loved ones. They may become confused, agitated, or aggressive.

The Alzheimer's Society of Canada lists these 10 warning signs to be aware of:

memory loss that affects day-to-day function

difficulty performing familiar tasks

problems with language

disorientation of time and place

poor or decreased judgment

problems with abstract thinking

misplacing things

changes in mood and behaviour

changes in personality

loss of initiative

Making the Diagnosis

Unfortunately, there's still no safe, definitive test for Alzheimer's disease. The diagnosis is made based on the type and progression of symptoms and by eliminating the many other possible causes of dementia, which include:

vascular dementia – caused by small strokes that damage brain tissue

nutritional and vitamin deficiencies, such as pernicious anemia or pellagra

liver, kidney, heart, lung, or thyroid disease, which can all cause temporary or permanent mental impairment

Parkinson's disease, Huntington's disease, or end-stage multiple sclerosis – the dementia of Parkinson's disease in particular can be hard to distinguish from Alzheimer's disease, as they share many symptoms

medications – several medications can cause symptoms (e.g., agitation, confusion, or disorientation) that look like Alzheimer's disease, including some pain medications and certain medications used for depression or anxiety – talk to your doctor or pharmacist to find out whether a medication you or a loved one is taking could cause these symptoms

These and other possible causes of dementia can mostly be identified with a few tests and questions. If the symptoms of Alzheimer's are present, and there's no other explanation for them, the physician will give a diagnosis of "probable Alzheimer's disease." This diagnosis is right 9 times out of 10.

Treatment and Prevention

Because there is currently no cure for Alzheimer's disease, treatment focuses on relieving symptoms and maintaining the quality of the person's life. Certain medications, called cholinesterase inhibitors, can help maintain brain function and delay the progression of the disease for several months to a year. People with moderate-to-advanced disease have been treated with a medication called memantine, which may provide additional benefit. This medication can also be used by people who do not tolerate cholinesterase inhibitors. However, the course of the disease is such that it eventually continues to worsen.

Fortunately, there are a number of ways to help people with Alzheimer's disease that do not involve medications. These include:

reminder notes

personal organizing tools such as date books and beepers

providing instructions for activities such as bathing, eating, and dressing

family counselling and support

behaviour training for inappropriate behaviours

The behaviour changes of Alzheimer's disease can be very distressing to people and their families or caregivers. Medications may be used to control severe agitation or behaviours which may result in physical harm or are very distressing to the person. However, in many cases agitation can be controlled without medications.

Not enough is known about the causes of Alzheimer's to provide clear advice about how to prevent it. Research into the effects of tobacco and alcohol is just getting underway, but there's still no hard evidence one way or the other. These drugs are clearly linked to other forms of dementia, however, it's a good idea for people who want their brains to stay healthy to avoid both.

An increased level of fitness helps the brain to stay healthy, so aerobic exercise may be a factor in either preventing or delaying the onset of Alzheimer's. Computerized "brain fitness" programs are becoming popular to keep the brain active and possibly protect it from deterioration. So far there is no convincing scientific evidence that this is effective in preventing Alzheimer's, but investigations are ongoing.

Contact your local Alzheimer's society for more information on new advances in research and suggestions for helping a person who has Alzheimer's disease.